This disclosure relates to the selection and usage of one or more different communication channels for sending electronic messages. Users may communicate using any of a variety of different communication channels. Typically, users have particular expectations as to what constitutes a normal or acceptable response time when sending a message. For example, when sending an electronic mail (email), a sender likely has an expectation as to when a response email should be received from the recipient. Similarly, when sending a text message, the sender likely has an expectation as to when a response text message should be received from the recipient. In some cases, the response time may be based upon social norms. In other cases, the response time may be based upon the personal expectations of the sender. The sender's expectations may differ from one communication channel to another.